In the popular and widespread Internet, an increasing number of services aim at providing content to an “open circle” of users which have not explicitly requested that particular content. A typical example is the placement of advertisements (ads) on web pages. Another example is a news service aiming at providing news of particular interest to users on web pages or as a newsletter via email push. Still another example is the provision of invitations or announcements in a business, public or private environment; consider, e.g. an invitation to an upcoming cultural event which shall be distributed via email to all interested people in a town.
A common characteristic to the above examples is that it is not possible to define in advance the users who may be interested in the content: In general, a user requesting a web page from, e.g., a search engine or a user being registered with its email address in a social network such as Facebook or MySpace may or may not be interested in receiving a particular advertisement, news or invitation. In case of business-related content distributions, however, a service provider will generally want to provide a personalized service, i.e. wants to target the provision of any particular content item to users who are actually interested in it.
Such targeting is also an important aspect from a network perspective: As untargeted advertisement emails, for example, require the largest available distribution list in order to eventually reach at least few interested users, such emails—widely known as spam—lead to considerable network load and crowded mail boxes. As the overwhelming majority of recipients is not interested in the ads, this leads to a waste of network and storage resources. In a mobile network environment, transmission resources over the radio interface as well as storage resources in mobile terminals are particularly limited; untargeted content distribution services definitively have to be avoided here.
In order to generally enable the provision of “open circle” services such as that exemplarily outlined above, efficient targeting mechanisms are required which allow selecting from a large group of users those who have a high likelihood of being interested in the content. In the advertisement field, companies such as Google and many others are highly involved in developing efficient targeting schemes. Such schemes will be of particular importance for mobile networks, as otherwise open circle services cannot be implemented therein from a practical point of view. Vice versa, provision of an efficient automatic targeting scheme for unrequested content items by a mobile network operator can lead to an improved usefulness of mobile networks for the users and improved benefits for the content providers.